Al-Zn-Mg-Cu合金組織與性能的影響
(中南大學 材料科學與工程學院， 長沙 410083)
摘 要: 采用光學顯微鏡和透射電鏡等分析手段研究了復(fù)合添加微量Cr、 Mn、 Ti、 Zr對Al-Zn-Mg-Cu合金板材組織性能的影響。 結(jié)果表明： 復(fù)合添加微量Cr、 Mn、 Ti、 Zr的Al-Zn-Mg-Cu合金具有最佳的再結(jié)晶抑制作用。 添加0.04%Ti+0.18%Zr、 0.20%Cr+0.20%Mn+0.04%Ti、0.04%Cr+0.05%Mn+0.04%Ti+0.18%Zr、0.20%Cr+0.20%Mn+0.03%Ti+0.17%Zr 4組微量元素， 合金的抗拉強度和延伸率依次提高；強度依次增加與所析出的共格、 半共格析出相種類增加、 彌散度增大、 粒徑增粗、 分布均勻性提高、 所占的體積分數(shù)增加有關(guān)， 合金延伸率增加與晶內(nèi)形成的微區(qū)無析出區(qū)均勻變形有關(guān)。
關(guān)鍵字: Al-Zn-Mg-Cu合金； 微量元素； 微觀組織； 強度； 延伸率
microstructure and mechanical properties of
Al-Zn-Mg-Cu based alloy
（School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: The effect of trace elements on the microstructure and testing properties of Al-Zn-Mg-Cu alloys were studied by optical microscopy and transmitting electron microscopy. The results show that with addition of 0.04%Ti+0.18%Zr, 0.20%Cr+0.20%Mn+0.04%Ti, 0.04%Cr+0.05%Mn+0.04% Ti+0.18%Zr, 0.20%Cr+0.20%Mn+0.03%Ti+0.17%Zr, respectively, the strength of the along increases, from 552.8 MPa to 711.3 MPa, and its elongation increases from 5.5% to 13.8%.The increase of the strength is related to the rising of the kinds of the phase which is coherent or semi-coherent to the matrix, the size of the particles, distribution heterogeneous and the percentage of the second phase volume. The increase of the elongation is related to the improvement of the alloy plasticity by precipitate free zone caused by quenching (Q-PFZ).The alloys with addition of Cr, Mn, Ti, Zr have the strongest effect on the recrystallization of the Al-Zn-Mg-Cu alloys.
Key words: Al-Zn-Mg-Cu alloy; trace element; microstructure; strength; elongation
